Importance of assessing biomarkers and physiological parameters of anemia-induced tissue hypoxia in the perioperative period

Abstract Anemia is associated with increased risk of Acute Kidney Injury (AKI), stroke and mortality in perioperative patients. We sought to understand the mechanism(s) by assessing the integrative physiological responses to anemia (kidney, brain), the degrees of anemia-induced tissue hypoxia, and associated biomarkers and physiological parameters. Experimental measurements demonstrate a linear relationship between blood Oxygen Content (CaO2) and renal microvascular PO2 (y = 0.30x + 6.9, r2= 0.75), demonstrating that renal hypoxia is proportional to the degree of anemia. This defines the kidney as a potential oxygen sensor during anemia. Further evidence of renal oxygen sensing is demonstrated by proportional increase in serum Erythropoietin (EPO) during anemia (y = 93.806*10−0.02, r2= 0.82). This data implicates systemic EPO levels as a biomarker of anemia-induced renal tissue hypoxia. By contrast, cerebral Oxygen Delivery (DO2) is defended by a profound proportional increase in Cerebral Blood Flow (CBF), minimizing tissue hypoxia in the brain, until more severe levels of anemia occur. We hypothesize that the kidney experiences profound early anemia-induced tissue hypoxia which contributes to adaptive mechanisms to preserve cerebral perfusion. At severe levels of anemia, renal hypoxia intensifies, and cerebral hypoxia occurs, possibly contributing to the mechanism(s) of AKI and stroke when adaptive mechanisms to preserve organ perfusion are overwhelmed. Clinical methods to detect renal tissue hypoxia (an early warning signal) and cerebral hypoxia (a later consequence of severe anemia) may inform clinical practice and support the assessment of clinical biomarkers (i.e., EPO) and physiological parameters (i.e., urinary PO2) of anemia-induced tissue hypoxia. This information may direct targeted treatment strategies to prevent adverse outcomes associated with anemia.

Intraoperative fluid balance and cardiac surgery-associated acute kidney injury: a multicenter prospective study

Abstract Background Recent data suggest the regime of fluid therapy intraoperatively in patients undergoing major surgeries may interfere in patient outcomes. The development of postoperative Acute Kidney Injury (AKI) has been associated with both Restrictive Fluid Balance (RFB) and Liberal Fluid Balance (LFB) during non-cardiac surgery. In patients undergoing cardiac surgery, this influence remains unclear. The study objective was to evaluate the relationship between intraoperative RFB vs. LFB and the incidence of Cardiac-Surgery-Associated AKI (CSA-AKI) and major postoperative outcomes in patients undergoing on-pump Coronary Artery Bypass Grafting (CABG). Methods This prospective, multicenter, observational cohort study was set at two high-complexity university hospitals in Brazil. Adult patients who required postoperative intensive care after undergoing elective on-pump CABG were allocated to two groups according to their intraoperative fluid strategy (RFB or LFB) with no intervention. Results The primary endpoint was CSA-AKI. The secondary outcomes were in-hospital mortality, cardiovascular complications, ICU Length of Stay (ICU-LOS), and Hospital LOS (H-LOS). After propensity score matching, 180 patients remained in each group. There was no difference in risk of CSA-AKI between the two groups (RR = 1.15; 95% CI, 0.85-1.56, p= 0.36). The in-hospital mortality, H-LOS and cardiovascular complications were higher in the LFB group. ICU-LOS was not significantly different between the two groups. ROCcurve analysis determined a fluid balance above 2500 mL to accurately predict in-hospital mortality. Conclusion Patients undergoing on-pump CABG with LFB when compared with patients with RFB present similar CSA-AKI rates and ICU-LOS, but higher in-hospital mortality, cardiovascular complications, and H-LOS.

Prevalencia de compromiso renal en pacientes pediátricos internados con enfermedad por coronavirus 2019: estudio multicéntrico / Prevalence of renal involvement among pediatric patients hospitalized due to coronavirus disease 2019: A multicenter study

Introducción. El compromiso renal (CR) en niñosinternados con enfermedad por coronavirus2019 (COVID-19, por su sigla en inglés) varía entre el 1,2 % y el 44 %. Dado que existe limitada información local, el objetivo primario de este estudio fue estimar la prevalencia de CR en nuestro medio. Población y métodos. Estudio transversalrealizado en 13 centros de Argentina entre marzo y diciembre de 2020. Se incluyeron pacientes internados con COVID-19, de 1 mes a 18 años y que tuvieran al menos una determinación de creatinina sérica y/o de orina completa.Se excluyeron aquellos con enfermedad renal conocida. Se consideró CR la presencia de lesión renal aguda (LRA), proteinuria, hematuria, leucocituria y/o hipertensión arterial (HTA). Resultados. De 528 historias clínicas elegibles, seincluyeron las de 423 pacientes (el 55,0 % de sexo masculino, mediana de edad 5,3 años). El cuadro clínico fue asintomático en el 31 %, leve en el 39,7 %, moderado en el 23,9 %, grave en el 1,2 %, crítico en el 0,7 %, y el 3,5 % presentó síndrome inflamatorio multisistémico pediátrico (SIMP). Dos pacientes (0,47 %) fallecieron. La prevalencia de CR fue del 10,8 % (intervalo de confianza 95% 8,2-14,2), expresada por leucocituria (16,9 %), proteinuria (16,0 %), hematuria (13,2 %), HTA (3,7 %) y LRA (2,3 %). Ninguno requirió diálisis. Presentar CR se asoció (p <0,0001) con formas graves de enfermedad. Conclusión. La prevalencia de CR en pacientes pediátricos internados con COVID-19 en 13 centros de nuestro país fue del 10,8 % y predominó en las formas clínicas graves.

Introduction. Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 1.2% and 44%. Given the limited information available locally, the primary objective of this study was to estimate the prevalence of renal involvement in our setting. Population and methods. Cross-sectional study conducted in 13 Argentine sites between March and December 2020. Patients aged 1 month to 18 years hospitalized due to COVID-19 and with at least one measurement of serum creatinine and/or a urinalysis were included. Those with a known kidney disease were excluded. Renal involvement was defined as the presence of acute kidney injury (AKI), proteinuria, hematuria, leukocyturia and/or arterial hypertension (HTN). Results. Among 528 eligible medical records, 423 patients were included (55.0% were males; median age: 5.3 years). The clinical presentation was asymptomatic in 31%; mild, in 39.7%; moderate, in 23.9%; severe, in 1.2%; critical, in 0.7%; and 3.5% had multisystem inflammatory syndrome in children (MIS-C). Two patients (0.47%) died. The prevalence of renal involvement was 10.8% (95% confidence interval: 8.2­14.2); it was described as leukocyturia (16.9%), proteinuria (16.0%), hematuria (13.2%), HTN (3.7%), and AKI (2.3%). No patient required dialysis. Renal involvement was associated with severe forms of disease (p < 0.0001). Conclusion. The prevalence of renal involvement among pediatric patients hospitalized due to COVID-19 in 13 Argentine sites was 10.8%; severe forms of disease prevailed.

McKittrick-Wheelock syndrome secondary to rectal adenocarcinoma

Introduction: McKittrick-Wheelock syndrome is a rare condition that arises from a hypersecretory state secondary to large colorectal tumors, mainly villous adenomas, leading to an electrolytic disorder associated with chronic diarrhea that usually persists for years. It is a relatively unknown disease that can lead to severe complications such as acute kidney injury, severe hyponatremia, and hypokalemia. In fact, it causes death in most untreated cases. Surgical removal of the tumor is the most successful treatment, and symptoms tend to disappear after proper management. Case Report: A 62-year-old man with a 2-year history of mucoid diarrhea preceded by abdominal pain presented with acute kidney injury, hyponatremia, and hypokalemia. A digital rectal examination and sigmoidoscopy were performed, and revealed a large laterally-spreading tumor in the rectum. Further investigation showed a rectal tubulovillous adenoma with secondary McKittrick-Wheelock syndrome. An anterior resection of the rectum with a colonic J-pouch and a diverting ileostomy were performed, and the patient improved with the resolution of the renal failure and electrolyte disturbances. The histopathological analysis revealed an invasive rectal adenocarcinoma. Discussion: McKittrick-Wheelock syndrome is a condition with a low incidence that needs early intervention and proper diagnosis. It is of extreme importance that this disease is included in the differential diagnoses for chronic diarrhea associated with an electrolytic disorder. (AU)

Evaluating TIMP-2 and IGFBP-7 as a predictive tool for kidney injury in ureteropelvic junction obstruction

ABSTRACT A major challenge in the management of ureteropelvic junction obstruction (UPJO) is the selection of patients who would benefit from surgical treatment. Tissue inhibitor metalloproteinase-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) indicate renal cell stress and are associated with cell cycle arrest. The [TIMP-2] [IGFBP7] ratio (Nephrocheck®) has been recently applied in patients in intensive care units patients to predict the development of acute kidney injury. In this study, we evaluated the performance of these biomarkers performance to distinguishing obstructive hydronephrosis (HN) from non-obstructive HN. Materials and Methods: Consecutive patients with UPJO were enrolled in this study. Urinary [TIMP-2] [IGFBP7] and clinical characteristics (hydronephrosis grade, differential renal function, and drainage half-time) were measured in the following groups: 26 children with obstructive HN at initial diagnosis (group 1A) and after six months of dismembered pyeloplasty (group 1B); 22 children with non-obstructive HN (group 2), and 26 children without any urinary tract condition, as the control group (group 3). Results: Comparing the initial samples, [TIMP-2] [IGFBP7] had higher levels in the HN groups and lower levels in the control group; however, no difference was observed between the HN groups (obstructive vs. non-obstructive). After six months of follow-up, patients who underwent dismembered pyeloplasty showed stability in the urinary concentration of [TIMP-2] [IGFBP7]. All patients with [TIMP-2] [IGFBP7] higher than 1.0 (ng/mL)2/1000 had diffuse cortical atrophy on ultrasonography. Conclusions: We showed that urinary levels of urinary [TIMP-2] [IGFBP7] are higher in children with HN than controls. Nephrocheck® is not reliable in predicting the need for surgical intervention for pediatric patients with UPJO.

Early predictive value of high density lipoprotein cholesterol for secondary acute kidney injury in sepsis patients / 中华烧伤杂志

Objective: To investigate the changes of high density lipoprotein cholesterol (HDL-C) in sepsis patients and its early predictive value for secondary acute kidney injury (AKI) in such patients. Methods: A retrospective case series study was conducted. From June 2019 to June 2021, 232 sepsis patients who met the inclusion criteria were admitted to the Second Hospital of Hebei Medical University, including 126 males and 106 females, aged 24 to 71 years. According to whether complicating secondary AKI, the patients were divided into non-AKI group (n=158) and AKI group (n=74). Data of patients between the two groups were compared and statistically analyzed with independent sample t test or chi-square test, including the sex, age, body mass index (BMI), body temperature, heart rate, primary infection site, combined underlying diseases, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score and sepsis-related organ failure assessment (SOFA) score at admission, and the serum levels of C-reactive protein (CRP), procalcitonin, creatinine, cystatin C, and HDL-C measured at diagnosis of sepsis. The multivariate logistic regression analysis was performed on the indicators with statistically significant differences between the two groups to screen the independent risk factors for developing secondary AKI in 232 sepsis patients, and the joint prediction model was established based on the independent risk factors. The receiver operating characteristic (ROC) curve of the independent risk factors and the joint prediction model predicting secondary AKI in 232 sepsis patients were drawn, and the area under the curve (AUC), the optimal threshold, and the sensitivity and specificity under the optimal threshold were calculated. The quality of the above-mentioned AUC was compared by Delong test, and the sensitivity and specificity under the optimal threshold were compared using chi-square test. Results: The sex, age, BMI, body temperature, heart rate, primary infection site, combined underlying diseases, and CRP level of patients between the two groups were similar (P>0.05). The procalcitonin, creatinine, cystatin C, and scores of APACHE Ⅱ and SOFA of patients in AKI group were all significantly higher than those in non-AKI group (with t values of -3.21, -16.14, -12.75, -11.13, and -12.88 respectively, P<0.01), while the HDL-C level of patients in AKI group was significantly lower than that in non-AKI group (t=6.33, P<0.01). Multivariate logistic regression analysis showed that creatinine, cystatin C, and HDL-C were the independent risk factors for secondary AKI in 232 sepsis patients (with odds ratios of 2.45, 1.68, and 2.12, respectively, 95% confidence intervals of 1.38-15.35, 1.06-3.86, and 0.86-2.56, respectively, P<0.01). The AUCs of ROC curves of creatinine, cystatin C, HDL-C, and the joint prediction model for predicting secondary AKI in 232 sepsis patients were 0.69, 0.79, 0.89, and 0.93, respectively (with 95% confidence intervals of 0.61-0.76, 0.72-0.85, 0.84-0.92, and 0.89-0.96, respectively, P values all below 0.01); the optimal threshold were 389.53 μmol/L, 1.56 mg/L, 0.63 mmol/L, and 0.48, respectively; the sensitivity under the optimal threshold were 76.6%, 81.4%, 89.7%, and 95.5%, respectively; the specificity under the optimal threshold values were 78.6%, 86.7%, 88.6%, and 96.6%, respectively. The AUC quality of cystatin C was significantly better than that of creatinine (z=2.34, P<0.05), the AUC quality and sensitivity and specificity under the optimal threshold of HDL-C were all significantly better than those of cystatin C (z=3.33, with χ2 values of 6.43 and 7.87, respectively, P<0.01) and creatinine (z=5.34, with χ2 values of 6.32 and 6.41, respectively, P<0.01); the AUC quality and sensitivity and specificity under the optimal threshold of the joint prediction model were all significantly better than those of creatinine, cystatin C, and HDL-C (with z values of 6.18, 4.50, and 2.06, respectively, χ2 values of 5.31, 7.23, 3.99, 6.56, 7.34, and 4.00, respectively, P<0.05 or P<0.01). Conclusions: HDL-C level in sepsis patients with secondary AKI is significantly lower than that in patients without secondary AKI. This is an independent risk factor for secondary AKI in sepsis patients with a diagnostic value being superior to that of creatinine and cystatin C. The combination of the aforementioned three indicators would have higher predicative valuable for secondary AKI in sepsis patients.

Value of urine IL-8, NGAL and KIM-1 for the early diagnosis of acute kidney injury in patients with ureteroscopic lithotripsy related urosepsis / 中华创伤杂志(英文版)

PURPOSE@#To investigate the clinical value of urine interleukin-18 (IL-8), neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) for the early diagnosis of acute kidney injury (AKI) in patients with ureteroscopic lithotripsy (URL) related urosepsis.@*METHODS@#A retrospective study was carried out in 157 patients with urosepsis after URL. The patients were divided into AKI group and non-AKI group according to the Kidigo guideline and urine IL-8, NGAL and KIM-1 levels were detected by enzyme-linked immunosorbent assay at 0, 4, 12, 24 and 48 h after the surgery. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of these three biomarkers for postoperative AKI.@*RESULTS@#The level of urine IL-8, NGAL and KIM-1 in AKI group was significantly higher than that in non-AKI group at 4, 12, 24 and 48 h (p < 0.01). The ROC analysis showed the combined detection of urine IL-8, NGAL and KIM-1 at 12 h had a larger area under curve (AUC) than a single marker (0.997, 95% CI: 0.991-0.998), and the sensitivity and specificity were 98.2% and 96.7%, respectively. Pearson correlation analysis showed that the levels of urine NGAL at 4, 12, 24 and 48 h in AKI patients were positively correlated with the levels of urine KIM-1 and IL-18 (p < 0.01).@*CONCLUSION@#AKI could be quickly recognized by the elevated level of urine IL-8, NGAL and KIM-1 in patients with URL-related urosepsis. Combined detection of the three urine biomarkers at 12 h after surgery had a better diagnostic performance, which may be an important reference for the early diagnosis of AKI.

Tiempo de ventilación mecánica invasiva y lesión renal aguda en pacientes críticos / Invasive Mechanical Ventilation Time and Acute Kidney Injury in Critically Ill Patients

Introducción: La evidencia científica vincula el uso de la ventilación mecánica invasiva con una mayor probabilidad de desarrollar lesión renal aguda, pero la falta de consenso sobre esta asociación no es infrecuente. Objetivo: Identificar la relación entre tiempos de ventilación mecánica y la aparición y gravedad de la lesión renal aguda. Métodos: Cohorte histórica realizada en una Unidad de Cuidados Intensivos del Distrito Federal, Brasil, entre 2016 y 2018. La población fue compuesta por 387 pacientes, pero la muestra consistió en 52 pacientes que necesitaron ventilación mecánica invasiva durante una semana y dos. El registro de los datos se realizó en un cuestionario estructurado compuesto por variables de identificación, datos clínicos, variables hemodinámicas y parámetros de laboratorio. Para los análisis de asociación se utilizaron las pruebas de Chi-cuadrado, Exacta de Fisher y Mann-Whitney. Los resultados con p < 0,05 se consideraron significativos. Resultados: La lesión renal aguda de diferentes severidades predominó en más de la mitad de los pacientes (55,80 por ciento), siendo el estadio 2 más prevalente (aproximadamente 30 por ciento ). Los pacientes que permanecieron en ventilación mecánica durante una semana o dos mostraron una disminución del riesgo de lesión renal aguda (OR 0,85; IC del 95 por ciento: 0,72 a 0,99, p = 0,038) y OR 0,77; IC 95 por ciento 0.63-0.94, p = 0,010, respectivamente). Conclusión: La lesión renal aguda de diferentes severidades estuvo presente en pacientes con ventilación mecánica invasiva. Sin embargo, el tiempo de ventilación mecánica solo no fue determinante de lesión renal aguda(AU)

Introduction: Scientific evidence associates the use of invasive mechanical ventilation with a higher probability of developing acute kidney injury, but the lack of consensus on this association is not uncommon. Objective: To identify the relationship between mechanical ventilation times and the onset and severity of acute kidney injury. Methods: Historical cohort carried out, between 2016 and 2018, in an intensive care unit of the Federal District, Brazil. The population consisted of 387 patients, but the sample consisted of 52 patients who required invasive mechanical ventilation for one week and two. The data were recorded with a structured questionnaire composed of identification variables, clinical data, hemodynamic variables and laboratory parameters. Chi-square, Fisher's exact and Mann-Whitney tests were used for the association analysis. Results with P < 0.05 were considered significant. Results: Acute kidney injury of different severity degrees predominated in more than half of the patients (55.80 percent), stage 2 being the most prevalent (approximately 30 percent). Patients who remained on mechanical ventilation for a week or two showed a decreased risk for acute kidney injury (OR: 0.85, 95 percent CI: 0.72-0.99, P = 0.038 and OR: 0.77, 95 percent CI: 0.63-0.94, P = 0.010, respectively). Conclusion: Acute kidney injury of different severity degrees was present in patients with invasive mechanical ventilation. However, the time of mechanical ventilation alone was not a determinant of acute kidney injury(AU)

Prognostic nutritional index and the risk of acute kidney injury in patients with acute coronary syndrome

SUMMARY OBJECTIVE Recent studies have linked malnutrition with undesirable outcomes in cardiovascular diseases. However, the underlying mechanism is unknown. Contrast-induced acute kidney injury (CI-AKI) increased cardiovascular mortality after percutaneous coronary intervention (PCI). This study hypothesizes that prognostic nutritional index (PNI) plays a role in the development of CI-AKI in patients with acute coronary syndrome undergoing emergency PCI. METHODS This study enrolled 551 patients. PNI was determined as 10× serum albumin (g/dL)+0.005×total lymphocyte count (mm3). CI-AKI was characterized as the increase in serum creatinine ≥0.3 mg/dL level within 48 h after PCI. Patients were classified as either CI-AKI (+) or CI-AKI (−). RESULTS CI-AKI has occurred in 72 of 551 patients (13.1%). PNI was significantly lower in the CI-AKI (+) group than in the CI-AKI (-) group (44.4±6.6 versus 47.2±5.8, p<0.001, respectively). Multivariate logistic regression analysis showed that PNI [odds ratio, OR: 1.631, 95% confidence interval (CI): 1.168-2.308, p=0.02] and estimated glomerular filtration rate (OR: 3.26, 95%CI 1.733-6.143, p<0.001) were independent risk factors for CI-AKI. CONCLUSIONS PNI is an independent risk factor for CI-AKI. The development of CI-AKI may be the mechanism responsible for the relationship between poor nutritional status and adverse cardiac events.

Prognostic Value of the Leuko-Glycaemic Index in the Postoperative Period of Coronary Artery Bypass Grafting

Abstract Introduction: High leuko-glycaemic index (LGI) (> 2000) has been associated with poor prognosis in many critical care settings. However, there is no evidence of LGI's prognostic value in the postoperative period of coronary artery bypass grafting (CABG). This study aims to analyze the prognostic value of LGI in the postoperative period of CABG. Methods: Single-center retrospective analysis of prospectively collected data was performed. Consecutive adult patients undergoing CABG between 2007 and 2019 were included. Blood glucose levels and white blood cells count were evaluated in the immediate postoperative period. LGI was calculated by multiplying both values and dividing them by 1,000 and analyzed in quartiles. Receiver operating characteristic curve was used to determine the best cutoff value. The primary combined endpoint was in-hospital mortality, low cardiac output (LCO), or acute kidney injury (AKI). Secondary endpoints included in-hospital death, AKI, atrial fibrillation, and LCO. Results: The study evaluated 3,813 patients undergoing CABG (88.5% male, 89.8% off-pump surgery, aged 64.6 years [standard deviation 9.6]). The median of LGI was 2,035. Presence of primary endpoint significantly increased per LGI quartile (9.2%, 9.7%, 11.8%, and 15%; P<0.001). High LGI was associated with increased occurrence of in-hospital mortality, LCO, AKI, and atrial fibrillation. The best prognostic cutoff value for primary endpoint was 2,000. In a multivariate logistic regression model, high LGI was independently associated with in-hospital death, LCO, or AKI. Conclusion: High LGI was an independent predictor of in-hospital mortality, LCO, or AKI in postoperative period of CABG. It was also associated with higher in-hospital death.

Síndrome cardiorrenal tipo 1 em região de baixo desenvolvimento: comparação entre os critérios akin e kdigo, necessidade de diálise e mortalidade / Type 1 cardiorenal syndrome in decompensated heart failure patients in a low-income region in brazil: incidence of acute kidney injury (akin and kdigo criteria), need for dialysis and mortality

Resumo Fundamento: A síndrome cardiorrenal tipo 1 associa-se a maior mortalidade em pacientes com insuficiência cardíaca (IC). No entanto, há escassez de publicações comparando critérios diagnósticos de lesão renal aguda (LRA). Objetivos: Analisar o perfil clinicofuncional de pacientes com IC e fatores associados a ocorrência de lesão renal aguda (LRA). Métodos: Estudo de coorte retrospectivo, em hospital terciário de região com baixo desenvolvimento econômico que incluiu pacientes com IC descompensada ou infarto agudo do miocárdio (IAM) recente, sendo avaliadas características clínicas, laboratoriais e ecocardiográficas comparativamente em pacientes com e sem LRA classificada pelos critérios Acute Kidney Network (AKIN) e Kidney Disease: Improving Global Outcomes (KDIGO). Nível de significância estatística com valor de p < 0,05. Resultados: Entre 81 pacientes, 61,73% evoluíram com LRA. A média de creatinina foi 1,79±1,0 mg/dL e de ureia 81,5±46,0 mg/dL, sendo maior no grupo com LRA (p < 0,05). Não foi evidenciada relação entre alterações cardíacas e redução da função renal. A doença renal crônica se associou a maior ocorrência de LRA (38% x 3,23% sem LRA, p = 0,001). Não houve diferença do KDIGO com relação ao critério AKIN. Os pacientes que desenvolveram LRA apresentaram maior mortalidade (32% x 9,8% no grupo sem LRA, p = 0,04, com odds ratio (OR) de 8,187 e intervalo de confiança 1,402-17,190, p = 0,020). Conclusão: Nessa casuística de pacientes com IC, a ocorrência de LRA foi elevada e foi fator de risco independente de mortalidade. As alterações cardíacas não se associaram à ocorrência de LRA, e os critérios diagnósticos KDIGO e AKIN apresentaram performance similar.

Abstract Background: Type 1 cardiorenal syndrome is associated with higher mortality in heart failure patients. However, few studies have compared the diagnostic criteria of acute kidney injury (AKI) in this population. Objective: To assess clinical and functional features and factors associated AKI in patients with heart failure. Method: Retrospective, cohort study on patients with decompensated heart failure or recent acute myocardial infarction, conducted in a tertiary hospital in a low-income region of Brazil. Clinical, laboratory and echocardiographic features were compared between patients with and without AKI according to the Acute Kidney Network (AKIN) and Kidney Disease: Improving Global Outcomes (KDIGO) criteria. The level of statistical significance was set at p < 0.05. Results: Of 81 patients, 61.73% had AKI. Mean creatinine and urea levels were 1.79±1.0 mg/dL and 81.5±46.0 mg/dL, respectively, and higher in the group with AKI (p < 0.05). No evidence of a relationship between cardiac changes and reduced renal function. Chronic renal disease was associated with higher prevalence of AKI. Higher mortality was observed in patients with AKI than in patients without AKI (32.0% vs. 9.8%, p = 0.04, OR 8.187 ad 95% confidence interval 1.402-17.190, p = 0.020). Conclusion: In this population of patients with heart failure, AKI was highly prevalent and considered an independent risk factor for mortality. Cardiac changes were not associated with AKI, and the KDIGO and AKIN criteria showed similar performance.

Evaluation of the prevalence and factors associated with acute kidney injury in a pediatric intensive care unit

Abstract Objective To assess the prevalence of acute kidney injury in pediatric intensive care unit according to diagnostic criteria - pediatric risk, injury, failure, loss, end-stage renal disease, Acute Kidney Injury Network and Acute Kidney Injury Work Group, or Kidney Disease: Improving Global Outcomes -, and determining factors associated with acute kidney injury as well as its outcome. Methodology This was a cross-sectional monocentric observational study, including patients aged between 29 days and 17 years who were admitted to the pediatric intensive care unit between January 1, 2012 and December 31, 2016. To evaluate the association between the study variables and acute kidney injury, the log-binomial generalized univariate and multivariate linear models were adjusted. Results The study included 1131 patients, with prevalence of acute kidney injury according to the Acute Kidney Injury Network and Kidney Disease: Improving Global Outcomes criteria of 12.6% and of 12.9% according to the pediatric risk, injury, failure, loss, end-stage renal disease. In the multivariate analysis of older children (PR 1.007, 95% CI: 1.005-1.009), sepsis (PR 1.641, 95% CI: 1.128-2.387), demand for ventilatory support (PR 1.547, 95% CI: 1.095-2.186), and use of vasoactive amines (PR 2.298, 95% CI: 1.681-3.142) constituted factors associated with statistical significance to the development of acute kidney injury. The mortality rate among those with acute kidney injury was 28.7%. Conclusion Older children, diagnosis of sepsis, demand for ventilatory support, and use of vasoactive amines were correlated with a higher risk of developing acute kidney injury. The mortality associated with acute kidney injury was elevated; it is crucial that all measures that ensure adequate renal perfusion are taken for patients with risk factors, to avoid the installation of the disease.

Dynamic Changes in Perioperative Cellular Inflammation and Acute Kidney Injury after Coronary Artery Bypass Grafting

Abstract Introduction: This study investigated the role of the neutrophil-lymphocyte ratio (NLR), the perioperative changes in NLR (delta-NLR), the platelet-lymphocyte ratio (PLR), and the platelet count in predicting acute kidney injury (AKI) following coronary artery bypass grafting (CABG) during hospital stay. Methods: The records of 396 patients with preoperative creatinine < 1.5 mg/dl undergoing isolated CABG between October 2015 and October 2019 were reviewed retrospectively. Diagnosis of AKI was based on the Kidney Disease Improving Global Outcomes definition. Demographic data, operative data, in-hospital mortality, preoperative NLR, PLR, and platelet counts were compared between patients with (AKI group) and without (non-AKI group) postoperative AKI. Additionally, NLR, delta-NLR, and PLR values were calculated daily for the first four postoperative days. A "subsequent AKI group" was formed for the first four postoperative days by excluding patients diagnosed with AKI. The daily and overall predictivity of the markers for AKI are investigated. Results: AKI was present in 86 patients during the postoperative period, while 310 patients had normal postoperative renal functions. NLR, delta-NLR, and PLR on the first four postoperative days (P<0.001 for all) were significantly associated with the development of AKI in subsequent days. Multivariate analysis identified postoperative NLR (odds ratio 1.17, 95% confidence interval 1.11-1.23; P<0.001) as an independent predictor of AKI. PLR lost its significant association with AKI at the values measured at discharge from hospital (P>0.05). Conclusion: NLR values measured on the first four days postoperatively are a useful tool in predicting AKI during hospital stay following CABG.

Renal replacement therapy by the popliteal vein in a critical patient with COVID-19 in the prone position / Terapia renal substitutiva pela veia poplítea em paciente crítico com COVID-19 na posição de pronação

Abstract This patient was a 73-year-old man who initially came to our service with acute respiratory failure secondary to COVID-19. Soon after hospitalization, he was submitted to orotracheal intubation and placed in the prone position to improve hypoxia, due to severe acute respiratory syndrome (SARS). On the third day of hospitalization, he developed acute oliguric kidney injury and volume overload. The nephrology service was activated to obtain deep venous access for renal replacement therapy (RRT). The patient could not be placed in the supine position due to significant hypoxemia. A 50-cm Permcath (MAHURKARTM, Covidien, Massachusetts, USA) was inserted through the left popliteal vein. This case report describes a possible challenging scenario that the interventional nephrologist may encounter when dealing with patients with COVID-19 with respiratory impairment in the prone position.

Resumo O paciente era um homem de 73 anos de idade que inicialmente veio ao nosso serviço com insuficiência respiratória aguda secundária à COVID-19. Logo após a internação, ele foi submetido à intubação orotraqueal e pronado para melhorar a hipóxia devido à síndrome respiratória aguda grave (SARS - do inglês "severe acute respiratory syndrome"). No terceiro dia de internação, o mesmo desenvolveu lesão renal aguda oligúrica e sobrecarga de volume. O serviço de nefrologia foi acionado para realizar acesso venoso profundo para terapia renal substitutiva (TRS). O paciente não pôde ser colocado na posição de decúbito dorsal devido a uma hipoxemia significativa. Um Permcath de 50 cm (MAHURKARTM, Covidien, Massachusetts, EUA) foi inserido através da veia poplítea esquerda. Este relato de caso descreve um possível cenário desafiador com o qual o nefrologista intervencionista pode se deparar ao lidar com pacientes com COVID-19 com problemas respiratórios e colocados em pronação.

Intraoperative oliguria does not predict postoperative acute kidney injury in major abdominal surgery: a cohort analysis / A oligúria intraoperatória não prediz lesão renal aguda pós-operatória em grandes cirurgias abdominais: Análise de uma coorte

Abstract Background: Acute kidney injury (AKI) is a common complication in patients undergoing major abdominal surgery and is associated with considerable morbidity and mortality. Several studies investigating the association between intraoperative urine output and postoperative AKI have shown conflicting results. Here, we investigated the association of intraoperative oliguria with postoperative AKI in a cohort of patients submitted to elective major abdominal surgery. Methods: This was a single-center retrospective analysis of adult patients who underwent elective major abdominal surgery from January 2016 to December 2018. AKI was defined according to the serum creatinine criteria of the KDIGO classification. Intraoperative oliguria was defined as urine output of less than 0.5 mL/kg/h. Risk factors were evaluated using multivariate logistic regression analysis. Results: A total of 165 patients were analyzed. In the first 48 h after surgery the incidence of AKI was 19.4%. Postoperative AKI was associated with hospital mortality (p=0.011). Twenty percent of patients developed intraoperative oliguria. There was no association between preexisting comorbidities and development of intraoperative oliguria. There was no correlation between the type of anesthesia used and occurrence of intraoperative oliguria, but longer anesthesia time was associated with intraoperative oliguria (p=0.007). Higher baseline SCr (p=0.001), need of vasoactive drugs (p=0.007), and NSAIDs use (p=0.022) were associated with development of intraoperative oliguria. Intraoperative oliguria was not associated with development of postoperative AKI (p=0.772), prolonged hospital stays (p=0.176) or in-hospital mortality (p=0.820). Conclusion: In this cohort of patients we demonstrated that intraoperative oliguria does not predict postoperative AKI in major abdominal surgery.

Resumo Introdução: Lesão renal aguda (LRA) é uma complicação comum em pacientes submetidos a grandes cirurgias abdominais, e está associada a considerável morbimortalidade. Vários estudos investigando a associação entre débito urinário intraoperatório e LRA pós-operatória mostraram resultados conflitantes. Neste trabalho investigamos a associação de oligúria intraoperatória com LRA pós-operatória em uma coorte de pacientes submetidos à grandes cirurgias abdominais. Métodos: Análise retrospectiva de centro único envolvendo pacientes adultos submetidos à grandes cirurgias abdominais, de janeiro de 2016 a dezembro de 2018. A LRA foi definida segundo critérios de creatinina da KDIGO. Definimos oligúria intraoperatória como débito urinário inferior a 0,5 mL/kg/h. Fatores de risco foram avaliados por análise de regressão logística multivariada. Resultados: Analisamos 165 pacientes. Nas primeiras 48 horas após a cirurgia, a incidência de LRA foi de 19,4%. LRA pós-operatória foi associada à mortalidade hospitalar (p = 0,011). 20% dos pacientes desenvolveram oligúria intraoperatória, sem associação com comorbidades preexistentes. Não houve correlação entre o tipo de anestesia e oligúria intraoperatória; entretanto, maior tempo de anestesia esteve associado à oligúria intraoperatória (p = 0,007). Maior creatinina sérica (Cr) inicial (p = 0,001), necessidade de drogas vasoativas (p = 0,007) e uso de AINEs (p = 0,022) foram associados à oligúria intraoperatória. Oligúria intraoperatória não foi associada ao desenvolvimento de LRA no pós-operatório (p = 0,772), à permanência hospitalar prolongada (p = 0,176) ou à mortalidade intra-hospitalar (p = 0,820). Conclusão: Demonstramos que a oligúria intraoperatória não prediz LRA pós-operatória em cirurgias abdominais de grande porte.

Biomarkers of acute kidney injury in patients with nephrotic syndrome / Biomarcadores de lesão renal aguda em pacientes com síndrome nefrótica

ABSTRACT Introduction: Emergence of acute kidney injury (AKI) in patients with nephrotic syndrome (NS) requires prompt diagnosis and differentiation between acute tubular necrosis (ATN) and proliferative glomerulonephritis. We studied the potential use of commercial urinary biomarkers' tests in the diagnosis of AKI in patients with NS. Methods: A cross sectional estimate of urinary concentrations of KIM-1 and NGAL was performed in 40 patients with NS: 9 with proliferative glomerulopathy, being 4 with AKI and 31 without proliferative glomerulopathy, being 15 with AKI. AKI was defined using the KDIGO criteria. Results: The mean age was 35 ± 16 years. The main diagnoses were focal and segmental glomerulosclerosis (10, 25%), membranous glomerulopathy (10, 25%), minimal change disease (7, 18%), lupus nephritis (6, 15%), and proliferative glomerulonephritis (3, 8%). Patients with ATN had higher levels of urinary KIM-1 (P = 0.0157) and NGAL (P = 0.023) than patients without ATN. The urinary concentrations of KIM-1 (P= 0.009) and NGAL (P= 0.002) were higher in patients with AKI than in patients without AKI. Urinary NGAL and KIM-1 levels were significantly higher in patients with ATN without proliferative glomerulonephritis than in patients with proliferative glomerulonephritis (P = 0.003 and P=0.024, respectively). Conclusions: Neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule 1 (KIM-1) estimates correlated with histological signs of ATN and were able to discriminate patients with AKI even in conditions of NS. Furthermore, urinary levels of NGAL and KIM-1 may be useful in the differential diagnosis of acute tubular necrosis and exudative glomerulonephritis in patients with nephrotic syndrome.

RESUMO Introdução: O surgimento de lesão renal aguda (LRA) em pacientes com síndrome nefrótica (SN) requer diagnóstico imediato e diferenciação entre necrose tubular aguda (NTA) e glomerulonefrite proliferativa. Avaliamos o uso potencial de testes de biomarcadores urinários comerciais no diagnóstico de LRA em pacientes com SN. Métodos: Uma estimativa transversal das concentrações urinárias de KIM-1 e NGAL foi realizada em 40 pacientes com SN: 9 com glomerulopatia proliferativa, sendo 4 com LRA e 31 sem glomerulopatia proliferativa, sendo 15 com LRA. A LRA foi definida usando os critérios da KDIGO. Resultados: A média de idade foi de 35 ± 16 anos. Os principais diagnósticos foram glomeruloesclerose segmentar e focal (10, 25%), glomerulopatia membranosa (10, 25%), doença por lesão mínima (7, 18%), nefrite lúpica (6, 15%) e glomerulonefrite proliferativa (3, 8 %). Os pacientes com NTA apresentaram níveis mais elevados de KIM-1 urinário (P = 0,0157) e NGAL (P = 0,023) do que pacientes sem NTA. As concentrações urinárias de KIM-1 (P = 0,009) e NGAL (P = 0,002) foram maiores em pacientes com LRA do que em pacientes sem LRA. Os níveis urinários de NGAL e KIM-1 foram significativamente maiores em pacientes com NTA sem glomerulonefrite proliferativa do que em pacientes com glomerulonefrite proliferativa (P = 0,003 e P = 0,024, respectivamente). Conclusões: As estimativas de lipocalina associada a gelatinase de neutrófilos (NGAL) e molécula de lesão renal 1 (KIM-1) se correlacionaram com sinais histológicos de NTA, e foram capazes de discriminar pacientes com LRA mesmo em condições de SN. Além disso, os níveis urinários de NGAL e KIM-1 podem ser úteis no diagnóstico diferencial de necrose tubular aguda e glomerulonefrite exsudativa em pacientes com síndrome nefrótica.

Acute kidney injury after heart valve surgery in elderly patients: any risk factors to modify?

Abstract Introduction: Postoperative acute kidney injury contributes to longer hospital stays and increased costs related to cardiac surgery in the elderly. We analyse the influence of the patient's age on risk factors for acute kidney injury after cardiac valve surgery. Methods: We evaluated the prevalence and risk factors for acute kidney injury in 939 consecutive patients undergoing valve surgery, between 2013 and 2018. Results: The prevalence of acute kidney injury was 19.5%. Hypertension (P=0.017); RR (95% CI): 1.74 (1.10-3.48), age ≥70 years (P=0.006); RR (95% CI): 1.79 (1.17-2.72), preoperative haematocrit <33% (P=0.009); RR (95% CI): 2.04 (1.19-3.48), glomerular filtration rate <60 ml/min/1.73 m2 (P<0.0001); RR (95%) CI: 2.36 (1.54-3.62) and cardiac catheterization <8 days before surgery (P=0.021); RR (95% CI): 2.15 (1.12-4.11) were identified as independent risk factors. In patients older than 70 years, with no kidney disease diagnosed preoperatively, glomerular filtration rate <70 ml/min/1.73 m2, male gender, cardiopulmonary bypass time, preoperative haematocrit <36% and preoperative therapy with angiotensin-converting enzyme inhibitors were risk factors for acute kidney injury after valve surgery. Conclusions: In elderly patients, postoperative acute kidney injury develops with higher values of preoperative glomerular filtration rate than those observed in a younger population. Preoperative correction of anaemia, discontinuation of angiotensin-converting enzyme inhibitors and surgical techniques reducing cardiopulmonary bypass time would be considered to reduce the prevalence of renal failure.

Research progress in influence of perioperative hypotension on postoperative outcome of patients / 中南大学学报(医学版)

With the advancement of disease treatments, the number of patients undergoing surgery worldwide is increasing. However, many patients still experience severe perioperative complications. Perioperative hypotension is one of the common side effects during surgery. Physiologically, perioperative hypotension can lead to insufficient perfusion of important organs and result in acute and chronic irreversible organ injury, which cause serious consequences for the patient's postoperative hospitalization and even the long-term outcome. Therefore, in order to optimize perioperative circulation management and improve the quality of life for patients after surgery, it is of great importance to investigate the relationship between perioperative hypotension and postoperative myocardial injury, ischemic stroke, postoperative delirium, acute kidney injury, and postoperative mortality. Individualized circulation management and reasonable application of vasoactive drugs may be the key point to early prevention and correct treatment of perioperative hypotension, which is of great significance for reducing perioperative related morbidity and mortality and improving the prognosis for the surgical patients.